About The V-Twin Engine

If you are into chopper's then you are probably familiar
with the v-twin
engine.

Do you know this type of engine is named a a V--Twin? It is
a two-cylinder engine layout in which the cylinders form a "V". The
engine's pistons are aligned so that, if viewed along the line of the
crankshaft, they appear to be in a V.

The V-twin configuration reduces the overall engine
length and weight compared to an equivalent straight engine (the straight
engine or in-line engine is an internal-combustion engine with all cylinders
aligned in one row.) This v-twin configuration allows for optimum torque for a
given displacement...POWER.

The v-twin engine can be mounted in the transversal position
(the definition of 'transversal' is a line extending or lying across at right
angles to the long axis.) V twins on Harley Davidson Motorcycles are mounted in a parallel
position. The longitudinal V Twin (the definition of longitudinal is:
length-ways, lengthwise) as seen on Moto-Guzzis and some Hondas is less common.
This position is well adapted to its transmission shafting, but has the
disadvantage of causing a torque reaction that tends to lean the motorcycle on
the side. The first VTwin was introduced in 1903, updated
with two and three-speed gearboxes.

The Indian was one of the first US makers to offer a
successful Twin in 1907.

The most obvious configuration for a Twin is a 90° angle,
but other angles can be achieved like the 45° Harley-Davidson.

Here's how a V Twin engine works...

A normal two cylinder engine fires the pistons in such a way
that one fires on the first revolution of the crankshaft, and the second one
first on the second revolution.

The engines runs quite smooth under this design.

But a Harley engine has two pistons, and the crankshaft has
only one pin (in the design above, which is a common design, there are two
crank pins for the connecting rods which the pistons connect to), and both
pistons are connected to it.

So the pistons fire almost at the same time. Whereas in the
example above they fire at different intervals.

This gives the choppers, and most particularly the
Harley Davidson its unique sound, throaty, in your gut...you know what I
mean...

This vtwin motorcycle is one of the early versions at 90
degrees...

As you probably know, the first choppers to come out with
this engine were the Harleys, so we can easily say that the vtwin engine was
born in the Harley Davidson's factories.

The Harley V Twin is generally credited to Bill Harley, who
designed it in 1908 as H-D's Chief Engineer. He went to work on the design
right after graduating from the University of Wisconsin in 1908. Those first
Harley V-twin engines proved to be a failure. In 1910, the (V)twin engine
dropped from Harley Davidson's line.

But it was soon re-designed and appeared again in 1911.

(V)twin's are not just for Harley's and Indian's. Many
manufacturers use the configuration on their bikes: Suzuki, Kawasaki, Yamaha,
Honda...all have V-twins.

To learn more about panhead
engines and v-twin engines and
other different types of engines, bookmark this page because we will be adding
more articles shortly.